Cleaning gases



May 6, 1924.,

A- N. DIEHL CLEANING GASES 2 Shee1s-Sheet 1 Filed AUE. 5, 1919 May 6,1924.

A. N- DIEHL.

CLEANING- GASES Filed Au 5, 1919 a sneezssn ez 2 ?eiensed hiley less.

.QEEEROSE I i. EEEHL, Q3 E UQUEINE, PENHS'ELVAIEE'M.

Amilioeflou sleiimigost 5, 1319. serial No. 315,520..

- eombnstible gases evolved in blast furnaces,

coke ovens, soil gas proaluoers and similar highly heated gases used inheating hot blast stoves, Ior hung steam boilers, in opereting gasengines, for. other lllflllS'i-Elill "purposes.

lne oligeet oi W a inventionis to provide a novel method leaning gasesby which impurities carried in suspension therein are readily removed ina rapid, effective Ztfitl economical manner. M

Another objee; of the invention is to proyide an improved method ofcleaning gases whereby the iitnpuz-ities in a flowing coluimi oi: theare separated and removed iiieieironi and wherein the separated1mpurities are collected and isolated and reshe flowing gas provide '1'improved method of c eaning gases eby the permeability of the screening'5. filtering medium lessenecl periodically in removing colleciions 0i?inipurities, the time required in .i'emoving the collected impurities isreduced and the re rno'val of collections of impurities from the path ofthe gases s greatly facilitated.

A still further object of myinvention is "to provide gas olemingapparatus having novel means whereby the travel of impuri ies inSliSPBIlSlOIllll the flowing colunm of gases is arrested, and theimpueities are separated from the gases withous interfer ence with. O1interruption in continuity of the gas flow.

Still fiiither objects of my invention e011- sist in the provision ofgas cleaning apps reins having the novel constructions, com binaeionsone}. arrangement of arts shown in the drawings, to he mox e fulydescribed hereinafter, end in be particularly specilied in theappencled apparatus claims.

Referring now to the drawings, forming part of ibis specification,Figure 1 is a (liegrnmmelsio plan. showing one arrangement of appointeeeonstzuefecl in accordance with my invention, end eds, terl for use inca'm'ying out the method invention Figure 2 is e similardiagrammatic-plan showing a inmlified form of apparel-fins embodying myinvention and adepteclfor use eerrying out the method forming part ofshe invention Figure 3 is s side elevation, partly in seclLlOI] showinge further modification in appar-ates embodying my invention, and a:-range, forming part of this invention.

Figure l is a diagrammatic plan of a portion. of the epper s tnsillossmte'cl in Figure 3 l Figure 5 is a sectional plnn'showing elemilsin she construction of a filtering screen adopted for "use in practicingthe method and; forming part of my iinnroveol apps arming part of myreins.

in Figures 1 and 2 of the accompanying drawings, the numeral 2designates the gas supply main. by which the gases to be cleaned areoonducted to one or the other of the two uplieete gaseleening chambers 3and i, and; 5 is the clean gas main into which the cleaned. gases passfrom the cleznn ing chambers and 4i,- and through which the clean gasesare led to a place of s orage or use.

The discharge end of the supply main 2 is forked, one branch 3 hazingconnected to the side inlet 7 on one end. of the cleaning Bl1t111l3l* 3and the other branch 8 being connected to the side inlet 9 on one end ofthe other gas'eleening chamber 4L. Suitable wolves and 11, which maybegate valves, enable the flow of gases from the supply main 2 to becontrolled alternately .di

fox use in eel-tying out the inefihotl rected into the chambers 3 and 4and, when necessary, to be entirely shut off from the chambers 3, 4;

The gas cleaning chan' bers 3 and 4 also are provided with side outlets12 and 13 on one end thereof, which open branches 14 and 15 on theforked inlet end of the clean gas main 5, this main 5 conducting thecleaned gases from the cleaning chambers to a place of use or storage.Valves 17 and 18 on the outlets 12 and 13 regulate and control the flowof gases from the cleaning chambers 3 and 4, and when closed preventback flow of gases into those chambers from the clean gas main 5.

Removably secured in each of the two cleaning chambers 3 and 4 is atransversely extending permeable or foraminous screen or filter 19.Manholes or openings (not shown) are provided in the side wall of thechambers 3 and 4 to permit of the'removal and replacement of thesescreens when found necessary or desirable.

The screens or filters 19 ordinarily will be formed of a pad or biscuitof steel wool, copper or brass wool, fiocculent asbestos, or asbestosfabric or a similar material not materially affected by heat, andpreferably the pads will be sandwiched between layers of woven wire orwire netting having a suitable mesh, as shown in Figure 5, or in anequivalent foraminous envelope.

The screens or filters also may be constructed of a sheet of woven wirefabric or netting rolled in a spiral coil or bundle or may be made ofsuperposed sheets of the woven wire fabric. Various other modificationsmay be used, the main object being to provide a construction which doesnot onduly obstruct the passage of the gases while presenting a largesurface for the impurities to strike and become deposited upon.

Eachof the cleaning chambers 3, 4, is provided on one end with a branchoutlet 20 or 21' which is connected by a conduit or pipe 22 to acentrifugal separator 23. Valves 24, 25, are provided to close thebranch outlets 20 and 21, and the separators are p1 vided with outletsconnected to the conduits 26. The conduits preferably connect into thegas supply main 2 at a point behind the forked outlet end thereof so asto discharge gases from the separators 23 into the gas supply main 2,

In the construction shown in Figure 1, exhausters or vacuum fans 27, 27are provided on the conduits 22 leading from the outlets 20, 21 towithdraw gases" from the cleaning chambers 3 and 4, as is done whencleaning the filtering screens 19 located in the cleaning chambers 3, 4.i

The gases withdrawn from the separators in the filter cleaningoperations are maintained at a higher pressure than the gases in thesupply' main by the exhausters 27, and

into the.

therefore, will flow into the main 2, although when considered advisableor necessary, automatically operating check valves will be provided toprevent the flow of gases from the main 2 through the pipes 26 into theseparators 23. The bottom of each separator will be provided with theusual outlet (not shown), through which collected impurities will beremoved at intervals from the separators.

The opposite or clean gas end of each cleaning chamber 3, 4, is providedwith a branch gas inlet 28 or 29, with valves 30 and 31 to control theHow of gases through these inlets.

In the construction shown in Figure 1, the branch inlets 28 and 29 onthe clean gas end of the cleaning chambers 3,4, are connected by thepipes 28 29 and 'Ts 34, to air inlet pipes 32, 33, and also areconnected by the branches 32, 33 of the Ts 34, 35 with the cleaned gasmain 5. Valves 36 and 37, 38 and 39, afford means for regulating andcontrolling the supply of gas or air drawn backwardly through the/inlets28.29 into the gas cleaning chambers 3, 4, in cleaning the screens orfilters 19 in these chambers.

In the modified construction shown in Figure 2, the branch inlets 28,29, on the cleaning chambers are connected by pipes 40, 41 to thedischarge outlet of fans or pressure blowers 42, 43, these blowers beingemployed to force gas or air, backwardly through the gas cleaningchambers 3, 4, at a suitably high velocity, in cleaning the filteringscreens 19 by removing the collected impurities from the screens, aswill be later explaned.

In the construction shown'in Figures 3 and 4, the gas cleaning chamber44 of the apparatus is provided on one end with an inlet 45 for theimpurity laden gases or gases to be cleaned, the inlet being connectedto the gas supply main.46, and has an outlet 47 on its other end throughwhich the cleaned gases pass to the clean gas main 48; Rotatably securedin the cleaning chan'iber is a revolving diaphragm 49, this diaphragm being keyed or'otherwise fastened to a vertical shaft 50 which isrotatably mounted in bearings 51, 52, in opposite ends of the chamber44. The shaft 50 extends through one end of the cleaning chamber and isconnected by bevel gears 53, 54 to the armature shaft 55 of an electricmotor 56, the motor forming -means by which the diaphragm is intermit'tently rotated in the operation of the apparatus of Figures 3 and 4.

The diaphragm 49is provided with a series of transverse openings 57 andin each of these openings is a filtering screen 58 (see Figure 5),,constructed in a similar manner to the screens 19 described inconnection with the apparatus of Figures 1 and 2. The transverseopenings 57 are equally spaced on a circle in the diaphragm 49, and thegasthe :37 will he closed.

meagre cleaning chamber 14 is provided with a suit ably located branchoutlet 59 which has its inlet end in close proximity to hire lowermostsurface 60 of lhe rcvoluhle diaphragm and arranged to register with lhecircular row of transverse openings in the dis phrugm.

' The discharge end of ihe hruuch outlet 59 is connected to the inlet ofon cxhauster or vacuum fun 61, and the discharge outlet of the exhausteris connected to ihe tangential inlet 62 of a centrifugal separator '63.The separator 63 has a gas outlet 6 which preferably is connected intothe gas supply main so at a point behind the inlcr, 45 "to the gascleaning chamber 44.

In carrying out my improved method with the apparatus shown in Figures 1and 2, the chambers 3, 4, are ulternutely em ployed in cleaningthecases, one being used to clean gases, while the screen orlilter l9 inthe other chamber 3 is being cleaned this resulh heing attained byhaving certain of the valves forming part of theuppara-tus open, whilehaviur the others closed.

Assuming that. the chamber 3 of the uppuru'tus of Figure 1 is being usedto remove impurities from the gases, the valves 10 and 17, and eitherthe valve 38 or 39 will he open, and the valves 11 and 1d, 24-. 36 andin such case, the gases to be cleaned will pass from the supply main 2through the branches 6 and 7, into the chamber 3, and from the chamber 3through the branches ligand 1% into rho clean gas main The enteringgases pass through the filtering screen 19 in the chanr her 3, and inpenetrating; she permeable filtering medium 19, are relieved of theimpurities carried in suspension in the gases, the impurities beingretarded and collect ed on the surfaces of the medium forming the screenor filter l9.

'llhile the cleaning chamber 3 is being used to remove impurities fromgases flow iug thercthrough from the gas main 2, the other cleaningchamber 41- rill not he in on oration, and advantage is taken theinterruption in the gas cleaning operaiion in the chamber 4. to cleanthe screen or filter ii) in i e chamber 4:. lVhen cleaning the filter-19 in the chamber one or the other of the arrive '3 13 will he opened toadmit air or July couduii 32- or gusiroin hc clean undo 5 At ihc timethe ill he opened and the exhauster will he started in operation. Thisresults in a current of air or gas being drawn through the chamber efrom right. to left, or

in theopposite direction to that t arched. by the gases during; thecleaning operation: The exhuustcr creutesu partial vacuum in he chamberand in this the velocity of the gases oruir 5 baclnvzirdly through thechamber 4 is me.-

terielly increased, and on account of the increased velocity of thegases or air, the inn purities collected during ahegas icleuningoperation on the filtering screen 19 hrs quickly and thoroughly removedfrom the screen. The impurities removed from the filter or screen 19pass from the chamber 4: through the conduit 22 and exhaust er 28, andare discharged by the exhuuster into the to of the centrifugal separator23 with the exhausted gas or air, and during the possuge of theexhausted gases, the impurities therein will become separated and settlein the bottom of the separator while the gases pass through the outletinto thegus conduit By materially increasingthe i'elocity at which thegases puss hackwurdly through the screen. 19 in removing collectionsoiimpurities therefrom, it is necessary to use only a comparativelysmall amount of gas. On account of the increased velocity of the gasesused to remove collected impurities from the screen or filter the volumeisvery much smaller than that of thegrases from which ihe impurities areremoved and the time required for the cleaning operation. is very muchless than is necessary to remove the impurities from the gases cleaned.For example, in cleaning; 1000 cubic feet of gases at a pressure of sixinches of water snd having a dust content of five grains per cubic foot,approximately 5000 grains of dust will be removed and hecoi'ne depositedon the filteringor screening medium. Upon re er-sing the operutiorutoclean the screening or filtering mediumyin blowing of 100 cubic fees ofgases through the filharinggmedium, at say two pounds pressure, eachcubic foot of the gases usedfor removing collected impurities from lhescreening medium will contain approximately fifty grains of dust Afterthe pressure of the cleaning" reduced to normalcy forty-live of thefifty grains of duel Will readily become deposited by grovihy. The gasesemerging from the separal'or 23 through the conduit 26 preferably areled hook into fiche supply main 2, zinc us ithe pressu e of the 4'scharr'ed into the separator l :sed. hy the vacuum blower 27 to morethan. that of *l e flowing through the su 'iply main 2. uore is no ouchflow of gases from 'ihe main 2 into the conduil: Q6 and sepuru iu' :21.

After the screen 19 in tho chuniher 3 has collected enoughimpuritics onthe surfaces hereof to clog the screen or impede the passage of gasesthercthrough, the valves, and 17, and the open one of the valves 38, 39,will he closed, and the valves ll and 18., A and one or the other of theValves BS, 37. will be opened and in this way gases will he deliveredfrom the gas supply main 2 through the branches 8 and 9 into the throughthe filtering screen 19, will pass through the branches l3 and 15 intothe clean gas main At the same time, clean gases will be drawn throughthe cleaning chamber 3 by the vacuum blower or exhaust er 2? into theother of the centrifugal separa-tors and the gases-in the separator 23after the impurities are removed, will be led through the outlet intothe conduit 26 and from the-ronduit into the supply main 2 or,-

in some cases. as when air is used for cleaning the filtering screen 19,will be allowed to be discharged into the atmosphere.

With the apparatus shown in Figure 2, the method of operation will bethe same as has been described, except that the pressure blowers 42 and43 are employed in place of the exhausters 21'' in supplying the gasesused in cleaning the filtering screens 19. \Vith this apparatus thechamber 3 is used alternately with the chamber 4t in cleaning gases, theunused chamber being cleaned while not employed in cleaning gases in thesame manner as has been described, the gas cleaning and screen cleaningoperations be ing reversed. as in using the apparatus of Figure 1.

In practicing my paratus of Figures laden gases are delivered by the gassupply main 46, through the inlet45 into the bottom of the cleaningchamber 4%. and pass through the screen 58 in the series of openings 57in the diaphragm 49 within the cleaning chamber. The cleaned gases afterpassing through the series of filtering screens pass through thedischarge outlet 48 into the. clean gas main 48 and are led thereby to aplace of use or storage. It. will be noted that one of the series offiltering screens 58 in the apparatus of Figures 3 and 4 always is inregister with the. branch outlet 59 in the chamber, and while in suchposition the screen 58 is cleaned and impurities collected thereon areremoved.

When a screen is tobe cleaned,the exhaustcr 6i is started in operationto create a partial vacuum in the branch outlet 59 so as to cause thegases to flow from the upper end of the cleaning chamber 44 through theparticular screen 58 being cleaned into the barrel outlet 5!), and afterpassing through the exhauster 61 the gases used iucleaning the screensare discharged into the ceutritngal separator 63.

T he gas is withdrawn through the screen 58 in the reverse direction tothat in which the gas travels when being cleaned. and preterably at veryll'lllCll increased velocity, and effectively removes'all of theimpurities collected on the screen. (See Figure 3).

After one of the screens 58 is cleaned, as has been described, theintermittently operating motor 56 is started so as to move the methodwith the apapparent to those skilled in the art. Many 3 and at, theimpurity 'bers, to ICIHOVGCOllGCtBd impurities from the i set my hand. I

screens by removing collected impurities therefrom.

The advantages of my invention will he modifications in the constructionand arrangement of the'apparatus used in carrying out my improved methodmay be made. 1.;

The screens or filters may be constructed to vary the permeability ofthe filtering me dium so as to lessen the resistance to the passage ofthe gases during the cleaning operations and facilitate the rem val ofthe impurities on the screening or fil ering Ine dium, and other changesmay be made.

1.; The method of cleaning gases-which Consists in passing a flowingcolumn of gases through a filterin medium and thereby retarding andarresting impurities in the gases without interruption in the flow ofgems through the filtering medium, periodically stoppingthe flow ofuncleaned gases throng portions or" said filtering medium and pass ingareverse tlow of the cleaned gases through said portions of saidfiltering me dium, at a materially higher velocity than i said uncleanedgases to remove collected im purities from the filter, and separatingthe impurities from said reversed flow of gases.

2. Apparatus for cleaning gases comprisi ing a. gas supply main havingtwo branch each of said branches leading to an independent cleaningchamber, a clean gas main having branches connected to each of saidcleaning chambers, valves in each of said branches for cutting off theflow of gas therethrough, filters in each of said.-cleaning chambers,adapted to retard and arrest; impurities in the gases, means forWithdraw mg it in a reverse direction through said filters at a highervelocity than the gases to be cleaned are passed through saidchamfilters, means for separating the impurities from the withdrawngases, and means for directing the withdrawn gases after cleaningthereof into the gas suipply main.

In testimony whereof, have hereunto musaosn n. time lug gas from saidclean gas main and forcdill

